Is There Poison in Our Food? Concerns About BPA

For years, researchers have implicated Bisphenol A (BPA) as a cause of cancer, obesity, diabetes and more. What’s the story behind this chemical?
By Elizabeth Kolbert
February/March 2012
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Food container manufacturers such as Ziploc have responded to BPA concerns by removing it.

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The synthetic chemical bisphenol A (BPA) — often found in plastic containers and the linings of metal cans — is a potent, estrogen-mimicking compound that can leach from containers into food and water. In this interview, published by Yale Environment 360, an online magazine from the Yale School of Forestry and Environmental Studies, BPA researcher Frederick vom Saal of the University of Missouri’s Endocrine Disruptor Group harshly criticizes U.S. corporations and government regulators for covering up or ignoring what he believes are serious health risks of BPA. — MOTHER  

Yale Environment 360: Everyone’s heard of BPA, but I really don’t think people know what it is. What is it? 

Frederick vom Saal: Bisphenol A is derived from petroleum. You take benzene, this sort of basic building block that corporations like Exxon produce, and they sell this to corporations like Dow Chemical. And they’re the ones that turn this, through a manmade chemical reaction, into this chemical called Bisphenol A. And this is an extremely reactive chemical that has the shape that any biochemist will look at and say, “This chemical will act as an estrogen-mimicking hormonal chemical.”

Yale Environment 360: This chemical was originally investigated by... 

vom Saal: Charles Edward Dodds. He was a British chemist, one of the leading chemists of the 1930s and 40s, and he won the Nobel Prize for synthesizing a chemical — people would love to dig him up and take the prize away from him — called DES, diethylstilbesterol, which was given to millions of women and has destroyed the lives of many of them. They were looking for synthetic, orally-active estrogens. Bisphenol A is highly absorbed, unlike the natural hormones that are degraded almost immediately in the stomach. And DES is highly absorbed. DES is, both structurally and functionally, very similar to BPA. There are lots of other, much more sophisticated, 21st century molecular assays that show BPA is actually as potent, and in some cases more potent, than DES.

Yale Environment 360: And why can’t we use BPA, for example, as a birth control hormone? 

vom Saal: For the same reason we can’t use DES. It’s a cancer-causing chemical. When fetuses are exposed to it, we now know that it is related to increasing body weight. Also obesity, diabetes, heart disease, immune dysfunction including asthma and allergy, damage to every part of the reproductive system, including uterine fibroids, ovarian cysts in women, breast cancer. In men, low sperm counts, prostate cancer, abnormalities of the urethra that as they age, men can’t urinate normally — a major reason men go to the doctor. We are talking about billions of dollars of medical costs. And then from a neuro-biological point of view, attention deficit hyperactivity disorder, some learning disabilities, social behavior disruption. It causes the brain of a young animal to look like a senile, aged adult, old person, and is part of impaired memory. This chemical is related to many of the epidemics in the world — diabetes, obesity, neural behavioral problems, reproductive abnormalities, decreases in fertility, early puberty in girls.

Yale Environment 360: So you have this estrogen-mimicking chemical. Why do we put it into so many products? 

vom Saal: The idea that a chemist would study biology is new. Chemists who do chemical synthesis would look at that molecule and not see estrogen, okay. And they wouldn’t be aware that somebody had published that this was being considered to be a hormonal drug.

Yale Environment 360: But why is it in everything? 

vom Saal: Well, this is a molecule that when you put it together, you make my hard and clear glasses. This is a great-looking product. The problem is that if you put it into hot material, put it in a base of a little bit of an alkaline environment, then the bonds break apart. When it’s in chain-linked form, its polymer form, these molecules are not hormonally active. But when they break away and they’re free, it’s a hormone.

Yale Environment 360: But let’s say I took the BPA out of this chemical. Why not just take it out? 

vom Saal: Think of polycarbonate as a steel chain. And what you’re asking is — what if I take the steel out of that? You don’t have a steel chain. You can make that chain with something else, but it’s not going to have those characteristics. Now, actually they are making other polymer blends that have hard, clear characteristics. It’s taken them a long time to do that. In the 1950s when they did this, they were euphoric. They had made something that superficially they thought looked like glass. Now, as anybody who’s had any kind of polycarbonate item knows, after washing it a hundred times or so, you can’t see through it. Water starts penetrating it, breaking it down; it’s dissolving. And under extreme conditions, you can take polycarbonate and put it in a saltwater solution and heat it up, and within 20 or 30 days, most of it is completely dissolved. It’s just gone.

Yale Environment 360: So how did you identify it as something of concern?  

vom Saal: We were studying estrogens and their effects on fetuses, because we know that your natural hormone, estradiol, the International Cancer Registry labels that as a Class I carcinogen. Your lifetime risk of breast cancer is best described by your lifetime exposure to your own natural hormone, estradiol. You need that to reproduce. But humans didn’t used to live to 50 or 60. That wasn’t part of evolution, and — oops, you’re exposed to it that long, and then it’s involved in causing cancers in your body. And all of these other estrogens contribute to the estrogen load, because your body doesn’t know whether DES is estradiol or one of these other myriad of chemicals that can trick the body into thinking it’s being exposed to estrogens. Bisphenol A is on a list of chemicals that had been shown very clearly to mimic the efficacy of the natural hormone, estrogen.

The mantra about Bisphenol A is, “Even if it is an estrogen, it’s so weak, you don’t need to worry about it.” But that’s like saying Arnold Schwarzenegger is weak relative to Superman. Because estradiol can act below a part-per-trillion. That is such a staggeringly small drop in an Olympic-sized swimming pool, and it’s causing breast cancers. We are between 10 and a hundred to a thousand-million times lower than whatever toxicologists were thinking about. And what we did was, using human breast cancer cells, we were studying estrogen chemicals for their potency. And Bisphenol A lit up like a Christmas tree. We said, “Holy mackerel. What is it that would ever make anybody think this is weak?”

And we did an experiment, and we started off using a dose 25,000 times lower than anybody had ever studied. There had been one major NIH study on it. No one had really done a detailed examination of exposure during fetal and neonatal stages and childhood, when development’s occurring, when estrogens really damage the programming of the way your body’s going to function for the rest of life. This is what happened to the DES babies. At 20, they’re showing cancers nobody had ever seen before. The problem is, you don’t see them right away. Now, when you get into their uterus, it’s shaped like an hourglass; the fallopian tubes are all damaged. And now at age 50, they have over a three-fold increase in breast cancer. It took 50 years to see that. This is the signature of endocrine disruption.

We published that, and the chemical industry came after us, threatening us. All of the manufacturers called us up, threatened us.

Yale Environment 360: What year are we in? 

vom Saal: 1996. Then Dow Chemical sent somebody down and said, “Can we arrive at a mutually beneficial outcome, where you don’t publish this paper?” — which had already been accepted. I got a call a few weeks later, from somebody who said, “I’m aware that the chemical manufacturers are gearing up for a multi-million-dollar campaign about how great BPA is for babies,” borrowing a page out of Dutch Boy Paints, where, knowing lead kills babies, they targeted it as making your baby happy. So what you do is you target the product at the sub-population it’s actually going to seriously harm. These people are really sick. I mean somebody who would do that is, from my perspective, a sociopath.

Yale Environment 360: But now we’re 14 years on, and how many studies later? 

vom Saal: Okay, over 1,000. And what you have is regulatory agency after regulatory agency, locked into procedures decades out of date. And unable, they claim, due to their rules, to acknowledge the existence, literally of any modern science. It’s like if you were to develop polio, we’d have to put you in an iron lung because our regulatory system doesn’t allow any kind of modern approach to deal with this. But that’s our chemical regulatory system.

None of the regulatory agencies, all of which are heavily dominated by chemical industry interests — they just didn’t know what to do with this. And the choice is, they’ve got 100,000 chemicals in commerce. They actually have regulatory authority over a small number of them, because in the 1970s with the Toxic Substance Control Act, they grandfathered in 62,000 chemicals, including BPA, that are totally outside the regulatory system. So there’s no regulation of BPA.

But in January, 2010, the FDA did something remarkable — it reversed its position that BPA is safe, and said we agree with our science advisory agency that there is reason for concern for prostate cancer, for early puberty, for a variety of things. This was a huge breakthrough. Now we actually have a government agency that has accepted that this is a chemical to be avoided. But they said, “We’re sorry, but we do not have the authority to do that. We don’t even have the authority to go to the chemical industry and say, ‘What’s this in?’ We can’t even find that out.” It’s a grandfathered chemical.

Yale Environment 360: What could [the FDA] do? 

vom Saal: What the FDA said is, “We are working with Congress to try to get laws changed.” But changing the rules that we operate by, if we had a compliant industry, would take five to 10 years. And this is one extremely non-compliant industry. It’s almost a $10 billion-a-year product. You know, people don’t give up that kind of money.

And 100 percent of chemical industry-funded studies say this chemical is completely safe. Have you heard this before? Every chemical, every drug you look at, follow the money and it will tell you the outcome of the research. Independent scientists find harm. People either overtly or covertly working with chemical industry’s interests are finding no harm. None of the industry and corporate labs have any standing whatsoever in the scientific community. And their research is pathetic because it’s so totally out of date, and uses techniques that nobody would use in an experiment, and are 40, 50 years old.

Yale Environment 360: Could you just describe one of the experiments that your lab did? 

vom Saal: The first finding we had was that it created an abnormal prostate in a mouse fetus. And then we published in the Proceedings of the National Academy of Sciences that you could actually, using a very sophisticated technique, take out the organ, you section it and scan it into a computer. You can say how many dorsal ducts there are, what are the characteristics of these ducts. Then we take these ducts coming out of the urethra and we stain them with special stains that identify exactly which types of cells are in there, and whether they’re dividing or not. And what we found is the stem cells — worst of all things, because these are the cells that in adulthood transition and become the cancer cells — and they’re the target of Bisphenol A. And they’re growing abnormally; the ducts are all grossly malformed.

We also fed BPA to a pregnant mouse, at a dose that was a thousand-fold difference between what could cause any effect, and then took her sons and identified that there were abnormalities in prostate development. Another group picked that up and treated rats with Bisphenol A. And in adulthood, they developed early stage prostate cancer. And this group was able to relate that to a change in programming of genes that were associated with the transition into prostate cancer in humans.

Yale Environment 360: So on a practical level — as a woman who fed all three of her infant sons out of plastic bottles — how worried do all of us parents have to be, and what can people practically do to avoid this ubiquitous chemical? 

vom Saal: What we know is that estradiol and estrogens are risk factors for disease. And that means that if you take a hundred people, you know, seven or eight may get the disease, or ten, or more. And the other thing is that we know that among women, there’s a hundred-fold variation in the degree to which women respond to oral contraceptives, for instance. So what you cannot say is the fact that you did this to your children means automatically they’re going to have all these diseases. But it does increase their risk of various abnormalities that you would want to keep an eye on. But all of the diseases we’re talking about are multi-factorial, and with BPA, the whole rest of an individual’s lifestyle interacts with that. I mean, in our animals it is leading to obesity with no increase in eating. But it means that if you’ve been exposed to this and you start to show symptoms of obesity, you would want to take counter measures, recognizing that just having the person having eat what you eat, doesn’t work — because this chemical, we find that it’s reprogrammed genes in fat cells, to function differently. And they’re putting more fat into their fat cells. Their fat cells are huge, compared to normal fat cells. They’re just socking away more lipid in there. And there’s nothing that person can do about it. But you can still control that person’s diet and not allow that to happen. One of the things that I’ve done is, in our household, my wife and I, first of all, have gotten rid of any kind of polycarbonate plastic.

Yale Environment 360: Which means any kind of those hard plastic bottles? 

vom Saal: Hard, clear [bottles] that do not say "BPA free." They contain other chemicals that I would not recommend being exposed to. And the water in there is not pure, nor is it regulated. The best thing you can do for your water supply is buy a good in-house filtering system, and use public water that’s run through a reverse osmosis, carbon filter. And within a few months, relative to buying bottled water, you will be financially ahead. And you will be guaranteed to be drinking pure water. Okay. So the other thing is, any kind of water I put in a container, I put in a stainless steel container.

Yale Environment 360: And I once read you’ve said you only drink your beer out of bottles; we should not be using cans. 

vom Saal: There is no canned product in the United States that does not have BPA, with a very few exceptions. So we use no canned products at our house. When the Japanese changed their can lining — which NAMPA, the National Association of Metal Packagers Association, claims that life on Earth would end if we took away BPA. Well, guess what? The Japanese did that. You don’t find BPA in can linings in Japan.

There are a zillion alternatives to baby bottles [with BPA], and there are already alternatives to cans. So what [U.S. Senator Diane] Feinstein wants to do in the BPA bill is give the canning industry a finite amount of time to get it changed.

The other thing is when you change the can lining, you’d better change it to something that’s gone through not the traditional regulatory agency nonsense, with out-of-date testing methods. You’d better get the experts in this field together and say, “How do I determine whether this has endocrine disrupting activity?” Other people in this community can tell you that. But you will not get that out of the U.S. EPA.

Yale Environment 360: All this raises rather alarming questions about whether we can really be confident of anything, or any chemicals that we’re consuming. But your story suggests that even when we have very clear evidence that something is harmful, we can’t get rid of it. So what faith should we have in this system at all? Any? 

vom Saal: None. The system has fossilized to the point that it is absolutely perverting the sense that they are engaging in any kind of rational process of evaluating the health effects of chemicals. A group of us from the Endocrine Society, representatives of a large medical society, told the head of the [EPA] Office of Chemical Safety, “You people have spent over $100 million; you do not have a credible set of assays, you have accomplished nothing except wasting a lot of money on non-bid contracts, for which you got no data. And the contract labs you’re using are providing you garbage that are so out of range of acceptable performance limits. And you’re declaring them usable.”

And he rejected this. He got mad. We told him, “You don’t know what you’re doing. And unless you bring in endocrinologists who know how to study hormonally-active chemicals, you’re going nowhere.” And he didn’t want to hear that. And he’s going around telling people they have this wonderful program. It’s a lie; it is a fraud; it is absolutely intolerable that this kind of thing is going on.

Yale Environment 360: Now, you must get this all the time, but people must say, “Oh, you’re just being an alarmist.” What do you say to those folks? 

vom Saal: Look at the data. I mean, as a scientist, if you go beyond what the data show, you lose credibility and you’re finished. One of the reasons that I have credibility in this field is that I have never done more than explained when I read that list of what this does, each of them are supported by piles of publications, from different laboratories. And that is the process of validation of scientific findings. If these studies were only done once in one place and nobody could replicate them, I would not be including them in a list of harm caused by this chemical. This is the highest volume endocrine-disrupting chemical in commerce. We don’t know what products it’s in. We know that in animals, it causes extensive harm. There are now a whole series of human studies finding exactly the same relationship between the presence of Bisphenol A and the kind of harm shown in animals.

That scares me. I don’t think that’s alarmist. This is a chemical about which we know more than any other chemical with the exception of dioxin. Right now, it is the most studied chemical in the world. NIH [National Institutes of Health] has $30 million of ongoing studies of this chemical. Do you think that federal officials in Europe, the United States, Canada, and Japan, would all have this as the highest priority chemical to study, if there were only a few alarmists saying it was a problem?

Additional Resources: 

Information from the National Institute of Environmental Health Sciences
Information from the American Chemistry Council, Inc.
Information for Parents from the U.S. Department of Health and Human Services
Information from the Centers for Disease Control and Prevention
Coke, BPA and the Limits of Green Capitalism
BPA in Thanksgiving Canned Food (2011), from the Breast Cancer Fund 

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Post a comment below.


2/26/2012 6:11:12 PM
Just found this Scientific American article, which also cites vom Saal, Says polycarb products have the #7 on the bottom which I wasn't aware of and wasn't sure if it was mentioned previously. Thought it was good info for anyone else that is concerned. Thanks again!!

2/26/2012 5:59:25 PM
I was just curious if anyone knows of BPA concerns related to gardening equipment. Should I be concerned about using plastic planters, etc? I do believe BPA is harmful and stopped using plastic (everything) as soon as the "BPA free" baby bottles became available. We are hoping to move before summer so I'm doing most of my planting in pots for now so I can take them with me when we move. I've always used clay, glass, or stone pots simply due to my negative opinion of plastic (involving BPA and the Great Pacific Garbage Patch) however, this year I am in need of A LOT of pots and plastic ones are much cheaper than the alternatives. Of course, I don't want to poison my organically grown produce by using plastic pots! I greatly appreciate any helpful info on the topic. Thanks for the article!

Robert Browning
2/19/2012 1:22:27 AM
The moderator didn't like my previous post. OK I'll restate. If BPA is in effect a synthetic estrogen and allowing children to ingest it daily from just after birth, wouldn't it have an effect on sexual development. Therefore, if someone published a paper correlating the abnormal sexual development of children to BPA, you could get the public groundswell needed To get the type of media exposure needed to effectively eliminate BPA, you would need a headline something like "CAN PLASTIC MAKE YOU A HOMOSEXUAL?" The chemical companies, fearful of lawsuits, would eliminate BPA within weeks, not the decade that the author claims would be needed. You cannot fight multinationals on their turf and expect to win.

2/17/2012 10:32:53 PM
If you do a search for "BPA" on the Medscape site, you get several pages of references. The review article was the 2nd to last on page 4; "Bisphenol A: a Scientific Evaluation". Almost all the other references are summary articles of research papers, written by journalists and not usually giving enough info to evaluate the credibility of the original paper....Keep in mind, animal studies generally use absurdly hi level exposures, and differences in animal vs human systems may not make comparisons meaningful (cf- effects of Lasix in humans vs race horses). Human studies only show correlations and correlation does not prove causality...While BPA is related to estrogen, and therefore may have effects like estrogen, the usual exposure levels are so low that there doesn't seem to be any discernable effects on our health.

Nancy Myers
2/17/2012 6:53:12 PM
I can't get the link to go. Ironically, I search for bpa on medscape and the overwhelming majority of the search results were cautionary about BPA. Yes, yes, I agree, that's not proof of anything. Still, I'd welcome the link you reference, thanks.

Nancy Myers
2/17/2012 6:32:20 PM
See reply to the comment above yours - most bags are made of polyethylene, which does not contain BPA. Note also that canning jars don't have BPA, but canning lids do. Lastly, although some soups and tomato products are available in (bpa free) tetrapaks, ironically the paks themselves...aren't recyclable.

Nancy Myers
2/17/2012 6:30:12 PM
check with the supplier of the bags, but odds are very good that the vacuum pack bags are polyethylene, the most common resin used for bags. Polyethylene does not contain BPA.

2/1/2012 9:41:50 PM
I agree with what you are saying. I'll just add that I cited the progestin concentration because it is hard to imagine how powerful endocrine disruptors can be just looking at numbers.

2/1/2012 1:07:49 PM
The interviewee has vested interest in proving a "problem" exists in order to gain research funds. No problem; no funds. The majority of his publications were no doubt in the popular press, aimed at influencing the naive. ..The review artice I sited includes the whole of the medical lierature...Your example of a progestin- not an estrogen- is comparing apples to hub caps. They are neither the same class nor are the concentrations stated necessarily analogous & comparable...While some specific estrogens may be necessary but insufficient factors in the production of prostate ca, some estrogens are used in the treatement of prostate ca...By analogy, are all athletes capable of hitting a 90mph fastball? Are all athletes capable of blocking a 320lb defensive end? Can all athletes air dribble a soccer ball for 10 minutes? They're all athletes, so why not?...As the review artcle states "the human doses of BPA...are ORDERS of magnitude LOWER than acceptable daily intakes. ...There are no poisons, only poisonous doses. Even H2O & O2 are poisonous when taken in excess.

1/31/2012 11:48:16 PM
The legitimate medical literature? So the 43 published papers the interviewee had a hand in don't count him as an expert? ".001 to .1 mcg/Kg..." Doesn't sound like much until you see that levonorgestrel (a progestin) effectively renders women sterile with 99.7% certainty at concentrations of .3 mcg/Kg.

1/31/2012 12:00:01 AM
This sort of pseudo-scientific article does a great disservice to a public concerned about the health dangers we could be exposed to, possibly diverting attention & resources from real problems. Here's a review of the research from the legitimate medical literature : Part of its summary: " To evaluate the risk, if any, from BPA, investigations were undertaken to more precisely determine human exposure levels and more carefully study the validity of the low-dose effects reported. On the basis of the most realistic studies of BPA levels in food and drink, as well as in human urine, it has been estimated that human exposures, including those of children, are very low and range from about .001 to .1 mcg/kg body weight (bw)/day. The results of the additional toxicology studies indicated that the low-dose effects could not be consistently replicated. In light of this, a number of governments and agencies brought together independent expert panels to carefully evaluate the toxicologic studies and provide regulatory guidance. These panels came to a similar conclusion, namely, that low-dose effects have not been demonstrated. They also supported the acceptable daily intake levels previously calculated on the basis of high-dose effects shown in laboratory animals. Comparing these acceptable intakes with the best exposure estimates reveals that human doses of BPA from migration of the compound into food and drink are orders of magnitude lower than acceptable daily intakes. Thus, it is very unlikely that humans, including infants and young children, are at risk from the presence of BPA in consumer products."

1/30/2012 11:18:39 PM
Excellent article! I would like to know if we're missing a sentence here though: "Hard, clear [bottles] that do not say "BPA free." They contain other chemicals that I would not recommend being exposed to. And the water in there is not pure, nor is it regulated. "

J Hefner
1/30/2012 6:09:47 PM
I would like to know where to find the information on the vacuum packs also...are they safe to use?

Peri Fenton
1/30/2012 4:06:06 PM
So he no longer uses canned food in his household...........does he buy only frozen veges? I mean, I get that the best thing would be to grow and can your own, but aside from that, are the plastic bags frozen veges come in safe or at least "safer" than cans? What about the plastic bags I use with my vacuum packer? This aids me tremendously in being able to provide my own food, but are they safe?

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